Boom mounting and bracing



Feb. 18, 1930. H. L. MITCHELL ETAL 1,747,946 I BOOM MOUNTING AND BRACING Filed June 17, 1927 2 Sheets-$heet 1 INVENTOR.

A TTORNEY.

Feb. 18, 1930. H. L. MITCHELL ET AL BOOM MOUNTING AND BRACING Filed June 1 1927 2 Sheets-Sheet INVENTOR. {W M BY W W 4 WN A TTORNEY.

Patented Feb. 18, 1930 UNITED? STAT ES PATENT OFFICE HQIJGERLL MITCHELL AN 1) ROLF'L'JUNGKU LL, OF'MIII'WAUKEE, WISCONSIN, ASSIGNORS 3 TO' HARNISCHFEGER CORPORATION, OF MILWAUKEE, WISCONSIN BOOM MOUNTING AND BRAGING Origiiialapplication fiIed ApIiI 16,1926, SerialNo. 102,397. Dividedand this applicationfil'ed Ji1nea17, 1927.. Serial no: 199,448.

This invention: relatesin general to power shovels or the like and more particularly toa boomassembly and mounting for a machine of this kind, the, present application being a division of our co-pending application for equalizer for. driving chain .of power shovels, filed April-16,1926, .Serial'No. 102,397;

One object of the; invention'resides in the provision of improvedbracinggmeans for the boom which tends-t0 and normally does-aid in reliable and, effective in operation and easy and comparatively inexpensive. tomanufacture and apply. I

Other objects andadvantages. reside in certain. novel features of the construction, ar-

rangement and combination of. parts" which willbehereinafter more-fully described and particularly pointed out. in the appended claims, referencebeing hadto the accompanying. drawings forming apart ofthis specification, and in which:

1 Figure 1 is a'fragmentary view insideele- .vation of, the fragmentary view in side elevation-ofthe front end of a power shovel showing one embodiment ofthe invention F-igure.1;:i. I I QFigure-3 is. an enlargedsectional; view on line-3.73 of Figure 1.;.. p

Figure 2 is. a fragmentary plan view of Figure 4 is a view in; transverse section on line:4-.-.4i of Figure'3-g,

Figure 5 is a bottomplan view of the. cap

" employed in thestructure shown in Figure4;

and

, Figure 6-is a view in section on liner66.:of Flglllefl;

Referring to the drawings-the. numeral 1 designates generally a. power: shovel which has a revolving platform'2 mounted on suit.- able running gearor traction means. A boom 3 is provided and has its lower end or boom footv made up of apertured. arms: 4 loosely fitted: in sockets 5 provided at the forward end of they revolving platform 2. The boom foot isiso fitted in its socket as to permit the boom= to be raised andv lowered vertically about a horizontal axis andthe boom is also permitted to sway laterally to. a certain limit.- edextent. To positively interconnect: the boom foot and socketand yet permit these desirable movements, a pivot 6v is provided andextends through. openings 7: provided therefor'in the sockets and openings. 8 in thearms 4 of the boom foot- As illustrated in FigureG, the openings 8 are; sufficiently larger than the pivot 5't0 permit the boom to partake of the desirablelateral movement or side. sway.

A dipper stick 9 is mounted on theboom and carriesa suitable shovel or. the like (not shown). Suitable crowding mechanism designated generally at 11 is also provided and may be of. any desirable. type or construction.

The boom 3 is provided at each side-there.- of with brace rods .32 connected. to. the; boom at their upper ends bymeans'of' a bolt and nut. 33 and threaded at. their lower ends to receive nuts 34, rods 32 being providedwith the usual turnbuckles, as shown. A hollow cylindrical member 35 is fitted over the lower apertured lugs 36 which receive: a bolt 37 whereby member 35 is pivotally connected to the front end of frame 2, bolt 37 passing through a suitable lug; 38 with which the frame. may be provided, A spring 39 is arranged upon=each rod 32 and is compressed between nut 34 anda cap 40 loosely fitting'the rodand closing theopen end of member 35.

The cap 40 is provided with inwardly extend- ;ing, diametrically opposed flanges 41 spaced laterally from the cap body and adapted to 'fit between similarly outwardly extending that when. cap. 40 is: fitted. upon .member. 35

and given a quarter turn, the cap'will be locked in position, as more clearly shown in Fig. 5. Member 35 and cap 40 may be provided with apertured lugs 43 and 4A, respectively, the lugs being arranged to register when the cap is in locking position and receiving a bolt 45 for holding the cap in this position. By means of the construction just described, springs 39 provide a cushion to relieve the "boom, dipper stick, the shipper sudden shock which would otherwise occur due to;side swiping with the dipper, or acci-.

dental engagement with an obstruction, the springs being of equal tension and acting normally to hold the boom in alignment with the longitudinal center line of the revolving platform, but permitting the loosely mounted boom to partake of restrained side sway at the proper time.

, Not only does this construction permit' longitudinal movement of the rods with respect to the member 35, but also permits limited angular movement of the rod about the cover plate iOas a pivot, the construction being similar to a ball'and socket joint in this respect. This arrangement permits the boom to turn slightly about its longitudinal ares although the springs '39 tend to hold the boom in the position shown. v

The brace rods 32 andthe cushion means or springs39 associatedtherewith have been shown applied to the boom of a power shovel,

but of course they mayibeused with equal 1. In hoisting mechanism, the combination with a supporting member, and a boom loosely connected thereto for pivotal movement abouta relatively fixed axis transverse to said boom, of bracing rods connected to said boom on opposite sides thereof and extending outwardly at substantially equal acute angles with respect thereto, hollow cylindrical members arranged over the free ends of said rods and fixed to said supporting member, caps'loosely arranged on said rods and secured'to and closing the ends of said last- .named members, and springs arranged within the latter and'upon said bolts, said bolts being provided atsaid free ends thereof with means coacting with said caps to compress said springs wherebyv the latter act normally socket, a boom having a boom foot loosely fitted into the socket for swinging movement 7 i in a vertical plane and for limited side sway,

the supporting member and tensioned to'nor'- mally maintain the boom against side sway shaft and the various other parts from the,

or lateral movement while permitting lim ited side sway or lateral movement of the boom under the influence of shocks or excessive strains.

3. A machine of the character described comprising a supporting'member, a boom,

means for mounting the boom on the supporting member in such manner as topermit vertical swinging movement of the boom and also limited lateral movement thereof, and a pair of brace members directly connected with the boom and directly connected to the supporting member, each brace member being made up of telescopic sections and spring means tending to cause the sections to telescope and to subject each brace member to longitudinal tension.

a l. A machine of the character described comprising a supporting member, a boom, means for mounting the boom on the supporting member in such manner as to permit vertical swinging movement of the boom and also limited lateral movement thereof,

and a pair of brace members directly conc nected with the boom and directly connected.

to the supporting member, each brace member being made up'of telescopic sections,

-means for mounting the boom on the supporting member in such manner as to. per-- mit vertical swinging movement of the boom and also limited'lateral movement thereof, "and a pair of brace members directly connected with the boom anddirectly connected to the supporting member, each brace member being made up of relatively adjustable sections, each section having an abutment,

spring means cooperable with the abutments of the sections of each brace member to subject each brace member to longitudinal tension, the abutment of one sectionrbeing removable topermit of assembly! f i 6. A machine of the character fixed socket, a boom having a'boom foot loosedescribed comprising-a supporting member having a ly fitted in the socket, means coacting with the socket and the boom foot for constrainbrace members located on the oppositesides of the boom and directly connected to the boom and to the supporting member and tensioned to normally maintain the boom against side sway while permitting limited movement of this character under the influence of shocks or excessive strains.

7. A machine of the character described comprising a supporting member having a fixed socket, a boom having a boom foot loosely fitted in said socket, a pivot pin coacting with the socket and boom foot, the

boom foot having an opening receiving the, pivot pin, said opening being larger than.

the pivot pin to permit limited side sway of the boom, and yieldable brace members connectedto the boom and to the supporting memberand tensioned to normally maintain the boom against side sway while permitting limited movement of this character under the influence of shocks and strains.

8; A machine of the character described comprising a supporting member, a boom, means for mounting the boom on the supporting member for free vertical swinging and limited lateral'movement, and a pair of brace members connected to the opposite sides of an intermediate portion of the boom and pivotally connected with the supporting member at points spaced laterally from the boom foot, eachbrace member having spring means for subjecting it to longitudinal tension whereby the brace members normally constrain the boom to vertical swinging move ment and yield to allow the boom to partake of limited lateral movement and thus to absorb shocks and strains acting laterally and sidewise of the boom.

In witness whereof, we hereto affix our signatures.

- HOLGERL. MITCHELL.

ROLF LJUNGKULL. 

